Shiga University of Medical Science

Multiple randomized trials comparing wide local excision (WLE) with different peripheral margins have established recommended peripheral margins according to Breslow thickness (BT) in the National Comprehensive Cancer Network (NCCN) Guidelines. However, these clinical trials included only a small number of patients with acral melanoma (AM). Therefore, we aimed to compare the prognosis of different WLE peripheral margin cohorts with invasive sole AM.

We conducted a multi-institutional retrospective study of patients with sole AM and a BT greater than 2 mm. Survival outcomes were compared between two groups: those excised with a peripheral margin of 2 cm, as recommended by the NCCN Guidelines, and those excised with a peripheral margin of 1 cm.

This study included 336 patients (2 cm margin: n = 226; 1 cm margin, n = 110) with a median follow-up period of 43.1 months. In multivariate analyses, a peripheral margin of 1 cm did not negatively affect survival (local recurrence-free survival [LRFS]: hazard ratio [HR] 1.19, P = 0.38; disease-free survival [DFS]: HR 1.05, P = 0.75). Survival after propensity score matching showed no significant differences between the matched groups (each group: n = 103; 5-year LRFS: 70.6 % vs. 59.3 %, P = 0.13; 5-year DFS: 47.4 % vs. 54.0 %, P = 0.63).

A peripheral margin of 1 cm did not negatively influence the prognosis of patients with a sole AM and a BT greater than 2 mm. Narrower surgical margins may be acceptable to minimize morbidity without compromising survival.

Human fibroblast-like synovial cells (hFLSs) are essential in maintaining the structural integrity of the articular cartilage and promoting joint inflammation. These cells are highly responsive to various physical and chemical stimuli, many of which influence cellular processes through intracellular Ca²⁺ signaling and membrane ion channel activity. In this study, we investigated the role of the TREK-1 two-pore domain potassium (K2P) channel as a molecular sensor of arachidonic acid (AA) in FLSs. Patch-clamp recordings revealed an outwardly rectifying K⁺ conductance resistant to conventional K⁺ channel blockers (4-AP and TEA) but sensitive to inhibition by quinidine, a broad-spectrum K2P blocker. Activation of the TREK-1 channel with 4-(2-Butyl-6,7-dichloro-2-cyclopentyl-indan-1-on-5-yl) oxobutyric acid (DCPIB) and ML402 increased this current, and immunocytochemical staining demonstrated TREK-1 expression in hFLSs. AA exposure potentiated the K⁺ current in a concentration-dependent manner and caused hyperpolarization of the resting membrane potential, effects fully antagonized by pretreatment of the cells with spadin, a TREK-1 selective blocker. Fluorescent Ca²⁺ measurements showed that AA-induced variable increase in the intracellular Ca²⁺ concentration ([Ca²⁺]_i) in different FLSs, and spadin attenuated these responses, reducing the number of cells exhibiting oscillatory and sustained [Ca²⁺]_i elevations. In a nominally Ca²⁺-free medium, spadin had no effect, suggesting that TREK-1 channels regulate plasma membrane Ca²⁺ influx. Our findings provide the first electrophysiological and pharmacological evidence for the involvement of TREK-1 channels in AA-induced Ca²⁺ signaling in hFLSs.

The larynx of infants and neonates is occasionally challenging to identify using video laryngoscope. This study aimed to develop an artificial intelligence (AI)-assisted model that can identify the larynx, including the opening vocal cord and the arytenoid portion, on images obtained using a video laryngoscope.

First, 1197 images were extracted by the author from the 653 videos for train and validation data. An AI-assisted model for identifying the larynx was developed using YOLOv8n. Then, 399 images were selected from the additional 63 videos for the test data at every 150 frames.

The sensitivity, specificity, and area under the curve of the AI-assisted model for identifying the larynx were 0.74, 0.99, and 0.91, respectively. The AI model correctly identified the opening vocal cord and arytenoid portion in cases without obstacles. Esophageal misidentification of the larynx and undetected cases of the larynx caused by obstacles were observed.

The AI-assisted model effectively identified the larynx, including the opening vocal cord and the arytenoid portion, during video laryngoscopy and potentially can enhance the safety of tracheal intubation of infants and neonates. However, esophageal misidentification remains critical. Further studies are needed to refine the model and ensure its reliability in clinical practice.